Lockstitch sewing machine



May 27, 1941. M. ROBERTS LOCKSTITCH SEWING MACHINE Filed Dec. 16, 1938 (Ittomegs Patented May 27, 1941 LOCKSTITCH SEWING MACHINE Maurice Roberts, Leicester, England, assignor to United Shoe Machinery Corporation, Borough of Flemington, N. J., a corporation of New Jersey Application December 16, 1938, Serial No. 246,185

7 In Great Britain January 4,1938

17 Claims.

The present invention relates to sewing machines, and is particularly, but by no means exclusively, concerned with shoe outsole sewing machines of the lockstitch type, one example of which is described in U. S. Letters Patent to Gouldbourn et al. No. 2,056,670 of October 6, 1936.

In the U. S. Letters Patent of Gouldbourn et al. No. 2,049,369 of July 28, 1936, there is described a bobbin or locking thread case, for a rotary shuttle of a hook needle lockstitch sewing machine, such as is described in Patent No. 2,056,670, having extending downwardly from it a nose which serves to prevent the bobbin or locking thread, if for any reason it should become unduly slack, from bending so far rearwardly as to become caught by the beak of the rotary shuttle. The .bobbin case described in Patent No. 2,049,369 is supported by a pin, secured within the shuttle, eccentric to the axis about which the latter rotates, and is prevented from completely rotating with the shuttle by a groove in the front face of the bobbin case and a stationary member which enters the groove. The bobbin case can, however, oscillate slightly so as to allow the needle thread, when being passed over the bobbin case, to pass between the stationary member and the opposite sides of the groove. When it is desired to remove such a bobbin case from the shuttle for renewal of the bobbin or looking thread supply, the stationary member is moved away from in front of the bobbin case and the latter, being entirely surrounded by the shuttle, except for the nose, is then withdrawn from the shuttle by the operator grasping the nose with his fingers.

It has been observed that if the pin in the shuttle, on which the bobbin case is supported, or the bearing in the bobbin case becomes worn, the inner face of the nose is apt to come in contact with the rotating shuttle and to become so worn at the root of the nose that the nose breaks away from the bobbin case. Further a bobbin case having such a nose is expensive to manufacture.

The various objects of the present invention are to simplify the construction and prolong the useful life of a bobbin case, such as is above referred to, to facilitate removal from the machine and to reduce the initial cost of manufacture.

In an illustrative embodiment of the present invention hereinafter described, there is provided a bobbin or locking thread case for use within the shuttle of a lockstitch sewing machine, which bobbin case, when viewed from the front has a purely circular outline, that is, it does not have a nose such as has been above referred to; n with the use of which bobbin case difficulty in withdrawing it from the shuttle, due to the absence of the nose, is avoided by the provision of a lip-like projection on the exposed front face of the bobbin case extending transversely of the central axis of the bobbin case, and an ejector movable towards and from a position beneath the projection on the bobbin case for withdrawing it from the shuttle. While this form of the invention isof particular advantage when employed with a thread case which is not provided with a nose, it may be'found useful even with a thread case having a nose, the projection forming a gapwith the front face of the bObbincase into which the ejector extends. This feature of the invention is embodied in a machine provided with means for retaining the bobbin case in the shuttle, the ejector being actuable by mechanism connected with the means for actuating the retaining means towards and from the thread case to cause the bobbin thread case to be withdrawn when the retaining means is moved away from the shutltle.

To prevent the shuttle thread from moving rearwardly into the path of the shuttle beak, as hereinbefore referred to, which might occur since, in the illustrative embodiment of the invention, there is no nose on the bobbin case, there is provided a relatively stationary finger,. formed separately from the bobbin case, in front of which the shuttle thread passes from the bobbin case to the work. 7

Other features of the invention will be readily understood by one skilled in the art from the following description, taken in connection with the accompanying drawing, in which Fig. 1 is a View in front elevation of one of said illustrative embodiments; Fig. 2 is a view in side elevation of part of the mechanism shown in Fig. ,1; Fig. 3 is a view in front elevation of a bobbin case of this illustrative embodiment; and Fig. 4 is a sectional view on the line IVIV of Fig. 3. I

The bobbin or looking thread case I of the i1 lustrative embodiment is circular in shape, and is not provided with a nose, such as has hereinbefore been referred to, and the shuttle thread passes from a reel, of usual construction (not shown) rotatably mounted in the bobbin case, over a pin 3 secured in the bobbin case and extending across an opening 5 formed partly in the peripheral wall, and partly in the front wall of the case. The bobbin case I has on its front face a V-shaped groove 1 formed between two forwardly extending projections 91, H. A rounded projection I3 on a retainer member I5 is normally positioned in the groove 1. The projection l3 and groove 1 are so relatively positioned and dimensioned that the bobbin case I can rotate sufficiently to allow the front portion of a loop of needle thread to pass between them as the loop is being passed over the bobbin case. The projection 9 prevents the bobbin case from being rotated in one direction and the projection prevents the bobbin case from rotating in the opposite direction. To support the bobbin case I, there is formed in it a central boss IS in which is secured a sleeve 2|. The sleeve 2| forms a bearing for a pin 23 in the shuttle on which the bobbin caseis rotatably mounted. v

To enable the bobbin case readily to be removed from the pin 23 in the shuttle in the machine of the present invention, the bobbin case I has extending from its exposed front face a lip-like projection 25. The projection 25 extends forwardly and transversely towards the central axis of the bobbin case and of the rotary axis of the shuttle, and provides a gap between the projection and front face of the bobbin case into which the lower end of an ejector lever 21 may be moved. The ejector lever is pivoted at 29 to an arm 3| corresponding to the arm, referred to as II in Patent No. 1,991,456, to which the aforesaid retainer member I is secured, and is arranged to swing obliquely from the left towards and from engagement with the bobbin case. To avoid the possibility that the needle loops will be caught on the projection 25 when the bobbin case is in operative position, the projection 25 points in the direction in which the needle loops move across the exposed face of the bobbin case.

As in that patent, the arm 3| is-fixed on a horizontal shaft 33 rotatable in bearings above the shuttle, about which the retainer member l5 swings towards and from the front of the shuttle. To actuate and lock the retainermemher, there is rotatably mounted in parallel relation to the shaft 33 an actuating and. locking shaft 35 corresponding to the shaft 96 in Patent No. 1,991,456 and carrying a hand lever 31 by which it may be rotated. The mechanism connecting the shafts 33 and 35 is similar to that of the Patent No.-1,991,456 and includes a locking disk 39 on shaft 35 and a follower. arm 4| on the'shaft 33.

To.move the ejector lever 21 on its pivot towards and from the bobbin thread case, the upper end is held by a spring 43 against a cam 45 secured to the locking shaft 35, which shaft is rotated by the hand'lever 31. If the hand lever 31 is moved forwardly, the arm 3| is first unlocked and is then swung upwardly away from in front of the bobbin case. During the forward movement of the hand lever 31, the cam 45 allows the spring 43 to move the lower end of the. ejector lever to the right towards the gap between the projection 25 and the forward face of the bobbin case. Thereafter, upon continued movement forwardly of the hand lever 31 the ejector lever swings forwardly against the rear face of the projection in the direction of the shuttle axis, and upwardly with the arm 3| and withdraws the bobbin case from the shuttle. A new reel of thread may then .be placed in the bobbin case and the latter returned to the shuttle. When the aforesaid hand lever 31 is moved rearwardly, the arm 3| and ejector lever 21 are moved rearwardly and the lower end of the ejector lever engages the front face of the projection 25. Thereafter, during further rearward movement of the hand lever 31, the ejector lever 21 is moved to the left away from the thread case and the arm 3| is locked in position in front of the bobbin case.

To guard the beak of the shuttle from engagement with the shuttle thread, in the illustrative embodiment, the member l5 has at its lower end afinger 41 arranged with its free end forwardly of the path of the shuttle beak and pointed in the direction of shuttle rotation in front of which the shuttle thread extending from the bobbin case to the work passes. The finger, being between the shuttle thread and the path of the shuttle beak, prevents in a manner similar to the aforesaid nose on the bobbin case, the shuttle thread, if it should become sufiiciently slack, from bending rearwardly into the path of the beak and being caught thereby. The

front portion of the loop of needle thread, when the loop is being passed over the bobbin case by th'eshuttle and as it is being drawn down therefrom, also passes in front ofthe finger 41 and the finger, therefore, would also prevent the needle thread loop from being caught bythe shuttle beak during an idle rotation of the shuttle case after a needle loop has been'passed over the bobbin case and'b-efore that loop has been drawn down out of thepath of the beak.

'Thus, there are provided a durable, locking thread bobbin case of comparatively simple and inexpensive form, novel bobbin case ejecting means, and novel means to prevent the shuttle beak from engaging the shuttle and needle threads at undesired times during operation of themachine.

Having now particularly described the nature of the present invention, what is claimed is:

1. A lockstitch shoe sewing machine having, in combination, stitchforming devices including a hook needle, a rotary shuttle, a circular, bobbin thread case within the'shuttle having a projection on'its exposed face extending transversely of thecentral axis of the thread caseyand an ejector movable towards a position beneath the projection and away from the shuttle *tgwithdraw the thread case'from the shuttle.

2. A lockstitchshoe sewing machine having. in combination, stitch-forming devices including a hook needle, a rotary shuttle, a circular bobbin thread case havingv a projection extending inwardly from the circular margin thereof to form a gap with thefrontface of the thread case, a lever movable towards the gap trans versely of the axis of the thread case and away from the shuttle, and means for actuating the lever, first towards the gap in the thread case and then while within the gap, o withdraw the thread case from the shuttle;

3. A lockstitch shoe sewing. machine having, in combination, stitch-fuming devices including a hook needle. a rotary shuttle, a bobbinthread case within the shuttle, means movable towards and from the shuttle for retaining the thread case within the shuttle, mechanism actuable to move the thread case retaining means towards or from the shuttle and to lock or unlockjthe retaining means, and a thread case ejector normally out of engagement with the thread case actuated by said mechanismto engage the thread case when the retaining means isbeing unlocked and to withdraw the thread case. when the retaining means is moving away from the shuttle.

4. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a. rotary shuttle, a bobbin thread case within the shuttle; an arm movable towards and from the shuttle for retaining the thread case in the shuttle, an ejector movable into and out of engagement with the thread case, a hand operated member, andrconnections roin said member for locking, unlockingand swinging the arm towards and'from the shuttle, and forv actuating the ejector.

A lockstitch shoe sewing machine having, in combination, stitch-forming devices includin a hook needle, a rotary shuttle, a bobbin thread case within the shuttle, an arm'. movable towards and from the shuttle to retain the thread case in the shuttle, an ejector movable into and out of engagement with the thread case, a hand operated member, and connections from said member for locking, unlocking and swinging the arm towards and from the shuttle and for actuating the ejector towards and from the thread case to cause the thread case to be withdrawn as the arm swings away from the shuttle.

6. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, a bobbin thread case within the shuttle, an arm arranged to swing towards and from the shuttle for retaining the thread case in the shuttle, a hand lever for swinging the arm towards the shuttle and thereafter upon continued movement of the lever in the same direction for locking the arm in a position to maintain the thread case in the shuttle and a thread case ejector norm-ally out of engagement with the thread case actuated by the hand lever to engage the thread case when the retaining arm is being unlocked and to withdraw the thread case with the retaining arm when the retaining arm swings away from the shuttle;

'7. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, a bobbin thread case having a gap in its face, an arm arranged to move towards and from the shuttle for retaining the thread case in the shuttle, and an ejector lever pivoted on the retaining arm to swing obliquely towards and from the gap in the thread case for withdrawing the thread case from the shuttle when the retaining arm is being moved away from the shuttle.

8. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, a bobbin thread case within the shuttle, an arm arranged to swing towards and from the front of the shuttle for retaining the thread case in the shuttle, a hand lever for swinging the arm towards the shuttle and thereafter upon continued movement in the same direction for locking the arm in a position to retain the thread case in the shuttle, a cam operated by the hand lever and a thread case ejector lever engaging the cam and movable toward a-nd from the thread case when the cam is operated to cause the thread case to be withdrawn from the shuttle, said cam being shaped to cause the ejector lever to swing towards the thread case when the thread case retaining arm is being unlocked and away from the thread case when the thread case retaining arm is being locked.

9. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, a bobbin thread case within the shuttle, an arm arranged to swing towards and from the shuttle for retaining the thread case in the shuttle, a hand lever for swinging the arm towards the shuttle and thereafter upon continued movement in the same direction for locking the, arm in a position to retainj-the thread casein. the shuttle and for unlocking and swinging the arm away from the shuttle when the hand lever is actuated in the reverse direction, a cam'operated by the hand lever'and a thread case ejector ilever engaging the cam, said cam being shaped to cause the ejector"lever to swing towards the thread case when the hand lever is actuated to lo'ck'the thread case retaining arm and to swing away from the thread case upon movement of the hand lever in said reverse direction.

10. A lockstitch shoe sewing machine'having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, a bobbin thread case within the shuttle, a thread case ejector norm-ally out of engagement with the thread case, but movable laterally of the rotary axis of the shuttle towards and from engagement with the thread case and in the direction of the shuttle axis, while in engagement with the thread case to withdraw the thread case from the shuttle, and means for yieldingly actuating the ejector laterally of the shuttle axis towards the thread case.

11. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, a bobbin thread case within the shuttle, a thread case ejector normally but of engagement with the thread case, but movable laterally of the rotary axis of the shuttle towards and from engagement with the thread case and in the direction of the shuttle axis, while in engagement with the thread case to withdraw the thread case from the shuttle, and means for actuating the ejector including a hand lever for moving the ejector in the direction of the shuttle axis, and a spring for moving the ejector laterally of the shuttle axis towards the thread case.

12. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, and a circular bobbin thread case within the shuttle having a projection on its exposed front face extending inwardly from the circular margin and spaced from said front face to form a gap to facilitate withdrawal from the shuttle.

13. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, a bobbin thread case within the shuttle, an arm arranged to swing towards and from the shuttle for retaining the thread case in the shuttle, a hand lever for swinging the arm towards the shuttle and thereafter upon continued movement in the same direction for locking the arm in a position to retain the thread case in the shuttle, a thread case ejector lever movable towards and from the thread case transversely of the rotary axis of the shuttle to engage the thread case and in the direction of the shuttle axis to cause the thread case to be withdrawn from the shuttle, and yielding means for causing the ejector lever to move towards the thread case when the hand lever is actuated to unlock the thread case retaining arm.

14. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, .a rotary shuttle, a bobbin thread case within the shuttle, and means separate from the thread case between the bobbin thread extending from the thread case to the work and the shuttle for preventing the bobbin thread from being caught during rotation of the shuttle.

15. A lockstitch shoe sewing machine having,

in combination, stitch forming devices including a hook needle, a rotary shuttle, a bobbin" thread case within the shuttle, an arm movable towards and from the shuttle for retaining the thread case in the shuttle, and means on the retaining arm for preventing the bobbin thread from being caught during rotation of the shuttle.

16. A lockstitch shoe sewing machine having, in combination, stitch-forming devices including a hook needle, a rotary shuttle, a bobbin thread case within the shuttle, an arm movable towards and from the shuttle for retaining the thread case in the shuttle, and a finger on the thread case retaining arm arranged between the thread extending from the thread case to the work and the path of the shuttle beak with its free end 2,24a,eoc

pointed in the direction of shuttle rotation for preventing the bobbin thread from being caught by the shuttle beak.

17. A lockstitch shoe sewing machine having in combination, stitch-forming devices including a hook needle, a rotary shuttle, a circular bobbin thread case within the shuttle having a projection on its exposed front face extending transversely of the central axis of the thread case and pointing in the direction in which the loops of needle thread move across said face of the thread case, said projection being spaced from said front face to form a gap to facilitate withdrawal from the shuttle.

MAURICE ROBERTS. 

